1 files changed, 25 insertions, 0 deletions

diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 896df1cf6adc..6430016b98e8 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -44,6 +44,31 @@ config IRQSOFF_TRACER
 
               echo 0 > /debugfs/tracing/tracing_max_latency
 
+          (Note that kernel size and overhead increases with this option
+          enabled. This option and the preempt-off timing option can be
+          used together or separately.)
+
+config PREEMPT_TRACER
+        bool "Preemption-off Latency Tracer"
+        default n
+        depends on GENERIC_TIME
+        depends on PREEMPT
+        select TRACING
+        select TRACER_MAX_TRACE
+        help
+          This option measures the time spent in preemption off critical
+          sections, with microsecond accuracy.
+
+          The default measurement method is a maximum search, which is
+          disabled by default and can be runtime (re-)started
+          via:
+
+              echo 0 > /debugfs/tracing/tracing_max_latency
+
+          (Note that kernel size and overhead increases with this option
+          enabled. This option and the irqs-off timing option can be
+          used together or separately.)
+
 config SCHED_TRACER
         bool "Scheduling Latency Tracer"
         depends on DEBUG_KERNEL